This content is created by the Healthline editorial team and is funded by a third party sponsor. The content is objective, medically accurate, and adheres to Healthline's editorial standards and policies. The content is not directed, edited, approved, or otherwise influenced by the advertisers represented on this page, with exception of the potential recommendation of the broad topic area.

Causes of and Risk Factors for Osteoarthritis

What Causes Osteoarthritis?

Arthritis involves chronic inflammation of one or more joints in
the body. Osteoarthritis (OA) is the most common type of arthritis. In people
with OA, the cartilage in one or more joints deteriorates with time.

Cartilage is a tough, rubbery substance. Normally it protects
the ends of bones and allows joints to move easily. When the cartilage
degenerates, the smooth surfaces of bones in joints become pitted and rough.
This causes pain in the joint and can irritate the surrounding tissues. Over
time, the cartilage may wear away completely. Bones in the joint that rub
together can cause severe pain.

Some degradation of cartilage is part of the natural aging
process. However, not everyone develops OA. The reasons one person develops the
disease when someone similar does not is not well understood. Specific causes
of OA may vary from person to person.

Risk Factors for Osteoarthritis

Certain factors are known to
increase the risk of OA. Some of these factors are beyond your control. However, you can
reduce the risk of developing OA from damage caused by lifestyle factors such
as:

overuse of joints

obesity

posture

Family History

Osteoarthritis (OA) sometimes runs in families. If your parents
or siblings have OA, you’re more likely to as well.

Doctors don’t know why OA runs in families. No gene has yet been
identified as the cause of OA. Yet, many genes may contribute to OA risk.

Age

OA is directly connected to wear and tear on joints. It becomes
more common as people get older. According to the Centers for Disease
Control and Prevention, more than one-third of adults over the age of 65 have
symptoms of OA.

Gender

OA can affect both men and
women. According to the National Institutes
of Health, it’s slightly more common in men until age 45. After that, it’s
more common in women. This may reflect the different joint stressors
experienced by men and women at different ages.

Previous Injury

People
who have injured a joint are more likely to develop OA in that joint.

Obesity

Being overweight or obese puts increased stress and strain on
the body. This increases the risk of OA in the joints. Obese and overweight
people are particularly susceptible to OA in the:

knees

hips

spine

However,
obesity is also associated with OA in non-weight-bearing joints, such as those
in the hands. This suggests that extra
mechanical stress on the joints or weight alone may not increase OA risk.

Certain Occupations

Repetitive actions can put undue stress on joints. Occupations
that include such repetitive actions can increase OA risk. Job tasks associated
with an increased risk of OA include:

kneeling or squatting for more than an hour a day

lifting

climbing stairs

walking

People
who regularly participate in joint-intensive sports may also have an increased
OA risk.

Poor Posture

Sitting
or standing improperly can strain your joints. This can increase OA risk.

Other Types of Arthritis

Other types of arthritis can increase your risk of developing OA
later in life. These include:

gout

septic arthritis

rheumatoid arthritis

Other Medical Conditions

Medical conditions that affect joint health can affect your risk
for OA. For example, bleeding disorders can cause bleeding in the joints.
Conditions that affect blood flow or inflammation can also affect risk. Some
medical conditions associated with OA include:

osteonecrosis

Paget’s disease of bone

diabetes

gout

underactive thyroid

Osteoarthritis Triggers

Not everyone with OA has
symptoms all the time. Most people with OA have symptoms that come and go
throughout the day. Certain common triggers for OA symptoms have been
identified. However, specific triggers may vary from person to person.

Lack of Activity

Staying still too long can cause your joints to stiffen. This
makes movement more likely to hurt. Lack of activity during the night may
partially explain why OA pain is often worse when people wake up.

Stress

Research has linked stress to exaggerated perceptions of pain.

Weather Changes

Changes
in weather can worsen symptoms of OA. People with OA are often especially sensitive
to cold, damp weather.